A general gas turbine includes a compressor, a combustor, and a turbine. Further, the compressor compresses air introduced from an air inlet opening to provide high-temperature and high-pressure compression air, and the combustor combusts the compression air with a fuel supplied to the compression air, thereby obtaining the high-temperature and high-pressure combustion gas (a working fluid). The turbine is driven by the combustion gas to drive a generator connected to the turbine.
A conventional gas turbine combustor is configured such that a plurality of main combustion burners is arranged to surround around a pilot combustion burner, a pilot nozzle is incorporated into the pilot combustion burner, a main nozzle is incorporated into the main combustion burner, and the pilot combustion burner and the plurality of main combustion burners are arranged within an inner cylinder of a gas turbine.
Examples of such gas turbine combustor are disclosed in Patent Literatures 1 and 2. A gas turbine combustor described in Patent Literature 1 is configured with a pilot nozzle. The pilot nozzle is provided with a sleeve arranged at an outside of a main body forming a fuel passage, a cover ring arranged between the sleeve and the main body to form inner and outer air passages, and a nozzle tip 75 having a fuel injection nozzle communicating with the fuel passage and provided at a front end side of the cover ring. In addition, a gas turbine combustor described in Patent Literature 2 is configured such that a fuel nozzle is provided with a diffusion tip through which fuel or air, or a fuel-air mixture passes and which serves as a passage together with a main premixed circuit.